1. Field of the Invention
The present invention relates to a manufacturing method for forming an electrolytic plated film on an electroless plated film.
2. Discussion of the Background
In International Publication No. WO 01/13686, a method for forming wiring by a semi-additive method (SAP) is described. In such a method, an electroless copper-plated film is formed on an insulation layer. Then, on the electroless copper-plated film, a plating resist with an opening that exposes part of the film is formed. Next, an electrolytic copper-plated film is formed on the electroless copper-plated film exposed through the opening. Then, after the plating resist is removed using a resist-removing solution, the electroless copper-plated film is removed by an etchant. In doing so, a conductive pattern (wiring) is formed, made of an electroless copper-plated film and an electrolytic copper-plated film. Recently, wiring pitch has become finer, and trends require an even smaller L (wiring width)/S (wiring space). However, using a manufacturing method described in the above International Publication No. WO 01/13686, when etching an electroless copper-plated film, it is thought that an electrolytic copper-plated film made of the same material may also be etched. There is a concern that as a result, wiring may become narrower. Thus, it may be an option to form thicker electrolytic copper-plated film in an opening of a plating resist, while taking into consideration the etching amount in advance. However, in such a case, it is thought that the adhesiveness of the resist will be reduced because the width of the plating resist decreases (conversely, the aspect ratio increases). Accordingly, there is a concern that the plating resist may peel off, for example, while the substrate is being washed with water after development or being handled.
The contents of International Publication No. WO 01/13686 are incorporated herein by reference in their entirety in the present application.